In a surgical treatment, without performing a laparotomy or a thoracotomy, small holes are opened in the patient and a forceps or scissors or the like are inserted therein, and surgery in which a desired treatment (so-called endoscopic surgery) is applied to diseased biological tissue or the like in the body is performed. Recently, in these types of procedures, apart from forceps or scissors, a medical manipulator in which operations can be performed in the body with a higher degree of freedom is used.
For example, in Japanese Laid-Open Patent Publication No. 2011-072570, a medical manipulator, which is constituted as an electrosurgical scalpel, is disclosed. In such a medical manipulator, a gripper, which is capable of gripping and engaging an object to be treated, and which can be operated to be opened and closed and to change the posture thereof with respect to the shaft, is disposed on a distal end of a shaft that extends from a handle. In a surgical procedure in which the medical manipulator is used, a distal end working unit including the gripper is inserted into the body cavity, and biological tissue is gripped by the gripper and electrical current is applied thereto, whereby the biological tissue is cauterized.
Among attitude changing operations of the gripper, there are a rolling operation for rotating the gripper about a longitudinal axis thereof, and a tilting action which operates to swing the gripper with respect to the shaft. In the medical manipulator, which is equipped with a gripper in which the rolling operation is possible, for supplying an electrical current to the gripper, for example, a slip ring mechanism can be adopted.